1. Field of the Invention
The present invention relates to the field of the agriculture and farming, more particularly the invention refers to farming tools, such as discs blades, either of the flat or concave/convex type, for working the soil during farming and cultivating works. Even more particularly, the invention relates to a wavy disc, such as a coulter, for use in agricultural machines like cultivators, preferably in no-till implements.
2. Description of the Prior Art
Nowadays it is becoming more and more popular the farming including the use of multiple tools for working the soil with no-tillage before seeding, wherein such tools may include coulters and discs with sharp edges to cut the soil surface and the stubbles in order to open the soil to receive the seeds. These tools are generally mounted on cultivators and planter frames having all the implements to carry out cultivation, preferably the well know no-till cultivation.
For the above mentioned works several designed rotary discs or disc blades including waves and fluted cutting edges are employed to open the desired furrows to which purpose the correct and neat cutting of the stubbles and soil surface is necessary. During the working the discs rotate onto the soil and the waves of the discs cause pieces of soil to move up and jump undesirably out of the furrow thus making the activity very similar to the traditional tillage.
A desired effect of the waves in the blades is that the discs get a gearing coupling with the soil in order to have a better rotation different from the discs with cutting edges having no waves or flutes. With the wavy edges the disc blades rotate better as long as they are more sensitive to the soil surface as well as the pieces of soil are broken under a more energetic action. The waves and flutes in the cutting edges of the discs and coulters produces cuts and shearing in sections that are transverse to the moving direction of the machine what leads to a better handling of the soil surface as well as to an increased specific pressure onto the soil, however these discs cut the stubble and also partially remove too much soil particularly when the wave moves up at a rear part thereof when moving out of the soil surface.
Conventional coulters and discs are provided with different designs and number of waves and flutes but, generally all of the waves and flutes have a general sinusoidal and symmetric design. This is, each wave is comprised of a curve symmetric regarding to a crest or an axis thereof, with and upwardly curved side extending from a valley up to the crest and a curved side downwardly extending from the crest to an adjacent valley. This is basically a curve and a more particularly a sinusoid. In other words those waves or flutes are the result of a logarithmic or exponential function curves.
U.S. Pat. No. 2,908,338 to Hanrahan, discloses a metal made fluted coulter disc with a peripheral cutting edge lying within confines defined between opposite faces of the flutes, with the flutes being illustrated as sinusoidal waves.
U.S. Pat. No. 3,559,748 to Shelton discloses a fluted coulter having a peripheral edge with flutes shown and described as a sinusoidal pattern and a design to provide a substantially circular and straight cutting edge. Finally, U.S. Pat. No. 5,649,602 to Bruce, discloses and illustrates a wavy coulter with a plurality of sinusoidal and symmetric waves extending along respective axis that form an acute angle with the disc radius.
While the above mentioned coulters and discs have shown a better result as compared to the discs and coulters without waves it has been also shown that the same have not complied with the increasing requirements of having more and more accuracy and optimal results in the use of conventional cultivating and seeding machines, particularly no-till implements. In deed, the modern machines are seeking for a more exact and correct cutting of the stubble, for a less mechanical stresses, better and adequate penetration deep of the discs or blades into the soil, as well as a less removal of soil which inconvenient removal is generally a direct result of the use of the waves.
It would be therefore convenient to have a new disc blade or coulter capable of efficiently cutting the soil surface and stubble without inconveniently removing and moving up pieces of soil as well as capable of keeping and conserving a desired humidity in the soil, more particularly a disc or coulter capable of keeping a higher humidity as compared to the result of the discs without waves or flutes.